Nouveau is the X11 driver which should -- at a later stage -- offer 3D acceleration. Currently 2D support is quite useful and we are working on 3D acceleration and deobfuscating the source we inherited from the X11 nv driver.

Installing Nouveau from git using the latest git kernel and Debian GNU/linux unstable/experimental

dpkg -i nouveau-build-deps_1.0_all.deb # will complain about the dependencies
apt-get -f install # should install them along with the package
apt-get build-dep linux-image-2.6-amd64 # get all packages needed to compile a kernel
apt-get install xdev-utils kernel-package checkinstall

In case you'll want to deinstall all the packages afterwards you'll be able to:

There are also precompiled Debian GNU/linux kernel packages available for the AMD64 architecture. The download and compilation takes quite a long time.

This is the kind of recommended way to install Nouveau as of 12th september 2009. It's kind of a quick hack, but not so invasive to package management.

###
### Build the Nouveau driver stuff with the Nouveau kernel from git as user source in /home/source/nouveau
### on a Debian GNU/linux unstable system
### Kernel images are built using package manager, DDX and DRM are quick hack.
###

This is a loose compilation of commands. Be aware that these are not copy-and-paste-ready as e.g. some *
might match more than they should. It is no robust script or whatsoever, but only a help in setting Nouveau
git kernel up. You may copy-and-paste command by command and EDIT it. Only then execute it. Know what you
do!

Free document license, no warranty at all. Copy and modify at will on YOUR OWN RISK!
Questions and comments are welcome to jkl345 A l i c e - D S L . N E T

Ready built kernels may be found at http://www.alice-dsl.net/jkl345/Installations.html

The information below is considered obsolete especially the instructions to install modules from mesa/drm-git. The Nouveau driver is now maintained in a copy of the kernel tree which is synced frequently with latest Linus' git. You may find valuable additional information below though.

Now we have installed drm, we can install the Nouveau drivers themselves:

sudo apt-get install xserver-xorg-video-nouveau

Edit your /etc/X11/xorg.conf and specify the nouveau driver in the Device section.

Restart X. You will need to remove the binary nvidia kernel module.
Editing your xorg.conf may be as simple as the replacing nvidia or nv with nouveau; nouveau won’t be chosen automatically over nv yet in Debian.

If you find bugs related to the Debian packaging, please report the problem with the Debian bug tracker.

Q: I can't install xserver-xorg-video-nouveau, it says something like "linux-nouveau-modules not available"
A: Follow the "Installing Nouveau from Debian Experimental" instructions above; you must compile the drm modules which "Provide:" linux-nouveau-modules.

Q: I can't insert the drm module, it says something with "duplicated symbol"
A: Make sure that you haven't set CONFIG_DRM in your kernel config

Q: Compiling xf86-video-nouveau fails with "No nouveau_drm.h found".
A: Make sure that nouveau_drm.h lies in a path which can be found by your compiler. Best thing is to put it in the same directory as the headers of the other X11 drivers. Or add your include path to the makefile.